Treatment of hydrocarbons



Patented Jan. 16, 1940 UNITED STATES TREATMENT OF HYDROGARBONS Vladimir Ipatiefl andiHerman Pines, Chicago,

Ill., assignors to Universal Oil Products Company, Chicago, 111., a. corporation of Delaware No Drawing. Application December 17, 1936,

Serial No. 116,360 I 7 Claims. (or; 260-671) I. of aromatic hydrocarbons with olefinic hydrocarbons has been known for a considerable time, particularly when employing sulfuric acid as' a catalyst to further the reactions. However, the present invention differentiates from previous art II on this subject in the use of particular olefinic starting material which is decomposed in the course of the alkylation reactions and in the use of other types of catalyst than sulfuric acid. The

. type of reaction with which the invention is congo cerned is therefore distinctly novel over the prior art.

In one specific embodiment the present invention comprises the allsvlation of aromatic hydrocarbons in the presence of catalysts by olefins 25 formed by the depolymerization of olefins higher in molecular weight than butylenes, the process being essentially one of depolyalkylation.

According to the present invention any of the aromatic hydrocarbons may be alkylated including benzene and its homologs, mer'nbe'rsof the naphthalene series and members of the anthracene or higher polynuclear cyclic series, obviously with somewhat modified conditions of operation when alkylating different compounds, The olefins employed are all of higher molecular weight than propylene and preferably consist of compounds of at least 6-carbon atoms to the molecule since the ease of decomposition of the olefins to yield lower molecular weight olefinic residues increases generally with the molecular weight of the olefin. Thus,- the butenes, which may be considered as dimers of ethylene require very severe )nditions or their depolymerization' of the olefins the alkylation reactions become progressively easier to accomplish. Catalysts which may be employed in effecting the type of reactions which characterize the invention may The temperature of treatment of any comprise sulfuric acid, phosphoric acid, and anhydrous metal halides such as forexample, aluminum chloride, zinc chloride, and ferric chloride. The adaptation of these different alternative compounds will depend upon the compounds un- 6 dergoing reaction, the temperature and corresponding phase conditions found most suitable and the need for a more active ora less active catalyst. I

In conducting the process for the alkylation of 10 normally liquid aromatics with normally liquid olefins the simplest procedure is to add a proportioned mixture of the hydrocarbons to a liquid catalyst such as 96% sulfuric acid or 90- 100% orthophosphoric acid during vigorous agitation. ll

Such processes may be made continuousby intimately mixing streams of liquid acids and hydrocarbon mixtures and causing the materials to pass through mixing devices which maintain intimate contact for sufficient time to insure completion of the desired reactions. In any 'event when the reactions are complete as determined by tests, the hydrocarbon layer is separated from the acid layer by either gravitational settling or centrifuging and the hydrocarbon layer fraca mixture may be passed through a tortuouspath v in some type of baflied mixer to accomplish the same result.

given 5 aromaticwith higher molecular weight olefins to effect their alkylation with the olefin' depolymerization products will necessarily vary with the molecular weight of the olefin and the activity of the catalyst and other factors. Pressure may be used when temperatures substantially above atmospheric or approaching the boiling points of the hydrocarbons are employed, functioning principally to prevent loss of material by vaporization.

As a rule, however, the temperatureranges are low and are comprised within the approximate range of .0- C. so that pressure is seldom necessary.

To illustrate the type of reactions involved in the present process the following equation is 50 given which indicates the reactants and the principal product formed-when depolyalkylation is brought about between benzene and the dimers of isobutene which consists principally of 2,4,4-tri methylpentene-l and 2,4,4-trimethylpentene-2.

The equation is given for the first-named compound.

c o-oc Benzene 2,4,4-trimethylpentane-1 C- C p-ditertiarybutyl benzene It is evident from the course of the reaction as indicated by the above structural equation that the octene has undergone scission at the bond between the two central carbon atoms to leave two tertiary groups. Since similar products are obtained when di-isobutene produced by the polymerization of isobutene is substituted for the single compound in the above equation, it is evident that the 2-pentene derivative undergoes a similar splitting. In the case of olefins having an odd number of carbon atoms as heptenes or nonenes or higher molecular weight olefinic compounds the reactions will be of a somewhat more complicated nature since the break between the carbon atoms may occur at different points in the aliphatic chain and produce'diflferent types of alkylated benzene derivatives. For instance, a heptene may yield substantial quantities of propyl-butyl substituted compounds while a nonene may yield principally propyl derivatives due to its depolymerization into three molecules of propylene.

The following examples are given tov indicate results which are typical of the process though they are not given with the intention of unduly limiting the inventions scope.

A mixture consisting of parts by weight of a mixture of di-isobutenes boiling within the narrow range of 102-104" C. and 9'! parts by weight of benzene was added to parts by weight of 96% sulfuric acid, the rate of addition being slow enough to be consistent with the maintenance of substantially atmospheric temperature. After the total hydrocarbon mixture had been added, the agitation was stopped and the acid and hydrocarbon layers allowed to separate.

The hydrocarbon layer after neutralizing with dilute caustic soda was carefully fractionated to produce three fractions as listed below.

Fraction 164-178" C. consisting of about equal parts of mono tertiary butyl benzene and p-ditertiary butyl benzene with a melting point of 78 C.

Fraction 216250 C. containing'a major proportion of the p-ditertiary butyl benzene as in the first fraction.

A fraction boiling at Mil-154 C. under a pressure of 9 mm. absolute consisting principally of various tritertiary butyl benzenes as indicated by the analysis of the total fraction given below:

Example II In this case a mixture of tri-isobutenes and benzene in about the same proportions as in Example I was passed into sulfuric acid in the same manner. The same type of products were obtained as before a somewhat larger proportionate yield of 'the more highly alkylated compounds.

Example III Example IV In this case a suspension of 20 parts by weight of anhydrous aluminum chloride in 112 parts by weight of di-isobutene and 100 parts by weight of benzene was agitated for some time. at 0 C. while introducing a small but regular stream of hydrogen chloride. After separation of the aluminum chloride sludge from the hydrocarbon layer, it was found that the major portion of the products consisted of mono-ter.-butyl benzene.

The novelty and utility of the process of the present invention are evident from the foregoing specification and the numerical data presented although neither section is intended to be unduly limiting upon the proper scope of the invention.

By the term depolyalkylation, employed in the appended claims, we mean the herein described reaction wherein an olefin hydrocarbon is split or depolymerized into olefin fragments of lower molecular weight and wherein an aromatic hydrocarbon is alkylated by such olefin fragments.

We claim as our invention:

1. A process for producing alkylated aromatics which comprises subjecting a mixture of an arcmatic hydrocarbon and an olefin of higher molecular weight than butylene to depolyalkylation.

2. A process for producing alkylated aromatics which comprises subjecting a mixture of an aromatic hydrocarbon and an olefin of higher molecular weight than butylene to depolyalkylation in the presence of a polymerization catalyst and at a temperature within the approximate range of 0 to 50 C.

3. A process for producing alkylated aromatics which comprises subjecting a mixture of an aromatic hydrocarbon and an olefin of higher molecular weight than butylene to depolyalkylation in the presence of a mineral acid catalyst and at a temperature within the approximate range of 0 to 50 C.

4. A process for producing alkylated aromatics which comprises subjecting a mixture of an aromatic hydrocarbon and an olefin of higher molecular weight than butylene to depolyalkylation in the presence of a metallic halide catalyst and at a temperature within the approximate range of 0 to 50 C.

5. A process for producing alkylated aromatics which comprises subjecting a mixture of an aromatic hydrocarbon and an olefin of higher molecular weight than butylene to depolyalkylation in the presence of aluminum chloride and hydrogen chloride.

' 7. A process for producing alkylated aromatics which comprises subjecting a mixture 0! an aromatic hydrocarbon and a. butene polymer to de- 6. A process for producing alkylated aromatics which comprises subjecting a mixture of an arcmatic hydrocarbon and an olefin of higher molecular weight than butylene to depolyalkylation in the presence of aluminum chloride and hydrogen chloride and at a temperature of approximately 0 to 50 C.

polyalkylation.

VLADIMIR IPATIEFF. HERMAN PINES. 

